Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 16 of 16 for “"Abasic Sites"”.
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RAD51-MEDIATED ABASIC SITES PROTECTION PREVENTS REPLICATION FORK COLLAPSE.
… produces as a result DNA lesions, among which abasic (AP) sites are the most prevalent in genomic DNA, occurring at an estimated rate of 10,000 to 20,000 per cell per day. Under normal conditions, AP sites on double-stranded DNA are primarily repaired by the base-excision repair (BER) pathway. …
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High-resolution mapping of abasic sites and pyrimidine modifications in DNA
… leading to the formation of damage products. Abasic sites occur when a nucleobase is lost from DNA by hydrolysis and can lead to mutations and genomic instability. This thesis focuses on the development and application of methodology to map the location of abasic sites in DNA by …
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Mechanistic studies of bleomycin-mediated double-stranded DNA cleavage and structural studies of DNA containing normal and 4'-oxidized abasic sites
In order to examine the role of partial intercalation in double-stranded (ds) DNA cleavage mediated by a single bleomycin (BLM), a bulky group ([-cyclodextrin) was chemically attached to the polyamine tail of BLM A5 to prevent the intercalation of the bithiazole tail. The ability of this analog …
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Mechanism of Mismatch Repair Induced Mutagenesis in Somatic Hypermutation
… single-stranded DNA tracts contain abasic sites produced as a result of uracil excision by uracil-N-glycosylase. Synthesis opposite abasic sites activates translesion synthesis and results in the recruitment of polymerase eta and the subsequent production of A:T mutations. In this …
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A study of the formation of interstrand and intrastrand crosslinks through abasic site and cleaved abasic site chemistry
… damage is the formation of apurinic/apyrimidinic sites (known as abasic sites); which occur at least 10,000 times per cell per day. If left unrepaired, subsequent damages such as interstrand crosslinks or strand cleavage can arise. While numerous studies have been conducted on crosslinks and …
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Nitric oxide and peroxynitrite-induced cellular damage
… damage products including base modifications, abasic sites, and single⁻strand breaks. A more detailed analysis revealed that two pathways, direct sugar damage and cleavage of abasic sites, are most likely responsible for the observed strand breaks. Surprisingly, experiments performed with …
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Significance of DNA base excision repair in the maintenance of mitochondrial function in Saccharomyces cerevisiae /
… repairing various base modifications as well as abasic sites (AP sites). In this research, Saccharomyces cerevisiae (S. cerevisiae) BER gene knockout strains, including 3 single DNA glycosylase gene knockout strains and Ap endonuclease (Apn 1 p) knockout strain were used to examine the importance …
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Development of an analytical method to quantify the oxidative deoxyribose damage product 3'-phosphoglycolaldehyde induced by radiation, iron and peroxynitrite
… electrophilic terminal blocking groups and abasic sites capable of stopping polymerases, forming DNA-protein crosslinks and nucleobase adducts. These threats to the genetic integrity of cells are caused by exogenous and endogenous oxidizing agents and may contribute to diseases such as …
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Novel Structures of RAD51 Reveal Mechanisms in DNA Damage Repair and Genomic Stability
… filaments that reveal specific recognition of abasic sites. Finally, I show that RAD51 can bind RNA substrates, as established by RAD51 filament structures bound to ssRNA and a DNA : RNA hybrid. Collectively these structures and supporting biochemical experiments highlight new mechanisms of …
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Altered DNA Repair, Antioxidant and Cellular Proliferation Status as Determinants of Susceptibility to Methylmercury Toxicity in Vitro
… due to the accumulation of toxic intermediary abasic sites. Accordingly, our results provide the first evidence that Ogg1 status represents a critical determinant of risk for MeHg toxicity independent of cellular immortalization method, with variations in cellular proliferation and …
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Repair eXtreme - DNA repair proteins from Antarctic extremophiles
… and was particularly active on substrates with abasic sites or 5’ flaps. The fourth protein was initially annotated as a hypothetical protein, however in silico analysis revealed that it exhibited homology to NucS nucleases identified in archaea and bacteria. This NucS homolog is a monomeric …
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Determining molecular mechanisms of DNA Non-Homologous End Joining proteins
… 3' phosphoglycolates, 5' hydroxyl groups and abasic sites. Non-homologous end joining (NHEJ) is a major pathway responsible for the repair of these complex breaks. Proteins involved in NHEJ include the Ku 70/80 heterodimer, DNA-PKcs, processing proteins including Artemis and DNA polymerases µ …
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Molecule recognition of nucleic acids, nucleosides, nucleotides, and their derivatives
… of chemotherapy by reducing drug resistance. Abasic sites (AP sites) are the key intermediates in the BER pathway and promising targets for BER inhibition. In chapter 2, we report the synthesis of two small molecules specifically targeting at AP sites and the evaluation of their activity in …
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DNA Damage and Cell Death Mediated by Thymidylate Synthase Inhibitors: Role of UNG and SMUG1 DNA Glycosylase
… in the form of single-strand breaks and abasic sites. Interestingly, only the SMUG1-depleted cells show a significant increase in the lethal DNA double-strand breaks (DSBs) formed following 5-FU treatments. Overall, results from this study indicate that expression of SMUG1 is a key …
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The Loss Of Genomic Uracil Homeostasis And Aid-Dependent Accumulation Of Dna Damage In B Cell Lymphomas
… wide DNA damage dependent on AID. These include abasic sites and single- and double-strand breaks. In addition, the accumulation of DNA lesions reduces cell viability. These lesions are due in part to the attempted repair of uracils by uracil DNA glycosylase.</p>
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Recombination and Excision: DNA Repair Proteins in Prokaryotic Host-Virus Conflicts
… T-even phages, such as coliphage T4, to generate abasic sites that inhibit DNA replication, which constitutes a novel anti-phage defense mechanism. Many phages have evolved to introduce DNA modifications to avoid recognition and cleavage by bacterial nucleases, including CRISPR-Cas and restriction …